The ability to treat and prevent illness and improve human health requires not only a detailed understanding of the complex interplay of biological systems contributing to disease processes but also the mechanisms underlying the influence of social complexity on biological systems. A developmental systems science approach provides methods uniquely suited to elucidate the mechanisms by which social systems influence health by investigating their effects on modulating the interplay among biological systems during development. The proposed research adopts this approach by modeling multi-level networked systems over time in a well-established nonhuman primate model. We predict that the coordination and regulation of biological systems within individuals are critical to shaping health trajectories and are dynamically modulated by the complex network structure of individuals' social relationships.